A COMPUTER-SIMULATION OF THE MICROSTRUCTURE OF A PARTICULATE DISPERSION

A computational simulation of a dispersion of iron particles undertake n to study the influence of the magnetostatic interactions on the micr ostructure of a particle ensemble is reported herein. The simulation c onsiders an equilibrium state derived from an initial random state by the force-bias Monte Carlo technique. This method favors particle move s in the direction of the magnetostatic forces. A three dimensional en semble in zero field and a saturating field are studied. An approach w hich takes into account the magnetostatic interactions between cluster s by allowing Monte Carlo moves of whole clusters has been developed. This approach leads to the formation of extended networks consisting o f particles in strongly bound clusters which themselves interact and g ive rise to an extended network. This is similar to the long-range ord er observed in practical dispersions. The structure analysis is found to characterize the local order, being especially sensitive to anisotr opy in the order produced by an aligning field.